Global Solar Overbuild Calculator

Local-first tool for terawatt-scale solar planning and large-scale energy abundance.






About the Solar Overbuild Calculator

Solar only shines part of the day, so running on it around the clock means building more panels than your average load needs and storing the excess. The Solar Overbuild Calculator sizes that overbuild ratio and the storage required to hit a target reliability.

It's the core sizing tool behind every 'run on solar' claim, from a data center to a moonbase.

How to use it

  1. Set your base load and target reliability.
  2. Enter solar and storage assumptions.
  3. Run the calculator to read the overbuild ratio and storage size.
  4. See how battery sizing and panel count trade off.

How it works

To cover load through the night and cloudy spells, you overbuild generation and bank the surplus. The calculator finds the panel-to-load ratio and storage capacity that meet your reliability target, showing how the two substitute for each other — more storage lets you overbuild less, and vice versa.

It captures why 24/7 solar is a sizing problem, not a physics problem: with enough overbuild and storage, solar can carry a continuous load, and the calculator quantifies exactly how much of each you need.

Worked example

Targeting high reliability on a steady base load typically needs generation several times the average load plus a matching store — and the tool shows how adding storage lowers the panel overbuild you must pay for.

Frequently asked questions

What is overbuild ratio?

How much more generation you build than your average load, to cover gaps.

Why not just add batteries?

Storage and overbuild substitute for each other; the cheapest mix uses both.

Does this apply off-Earth?

Yes — the same logic sizes solar for a lunar or Mars base.

Engineering-grade?

No — a transparent first-order sizing estimate.

Free and multilingual?

Yes — 25 languages, browser-based.

Related tools

Solar + Data Center OptimizerMoonbase Integrated Energy SystemLunar & Orbital Power ArchitectPower Abundance Hub